COMP461 said:
I have never had a cam loose a lobe yet, doesn’t mean it will not happen someday. I have a good number of cams out there, and since this thread a good deal more sold and on the way to racers and quite a few pullers. . I spoke with my grinder today, and he confirmed that the cam is cast nodular steel, and is hardened deeper then could ever be reasonable ground. Cummins intended their cams to last and this is a primary reason for this material The hardness is well above 50 on the C scale to a depth of over .250 on the back side with a the hardness being sampled every .010 . It really doesn’t mater thou, because if a cam was ever to loose a lobe I would replace it.
For any one to even make a statement that the stock cam is almost too large in a nitrous application is to show a total lack of performance engine knowledge. Nitrous is just turbo in a bottle and when used, the byproduct it creates, is a huge increase in spent combustion gasses. This is a primary reason that nitrous motors especially need a dramatic increase in exhaust timing event. I do not use nitrous as the definitive power adder, but use nitrous to spool a even larger looser charger. I use a cam the same way. An advanced exhaust event will aid in spooling a charger , this is the reason and advantage to using the correct cam for the correct application . I have my cams in a multitude of different programs out there , including George’s truck “WICKED1 “ that finished second in the diesel power challenge, Industrial Injections truck has one of my billet cams. Wade truck has one , along with project X and many more .
To speak of, here is what a lost cam lobe looks like, this lobe was analyzed and the cam lobe was found to be at fault, it’s not a oil failure, with is apparent by the bearing.
Not pointing fingers but when a blatant comparison is made, and a untruth is told. I will correct it. And no I didn’t copy the grind from this cam, I do have the CAM DOCTOR print out from all on my competitors cams , and was very unimpressed with them, and if you can’t remember the numbers on your own cams I do have them , and the numbers at .006 , .050 . 200 and all tell a story. There is no similarity what so ever in my grinds and the competitor who babbles on here about. he is right and by golly we should accept it because he is who he is and that is that , and if we don’t like it , he will stomp his feet and change his name and well what every else he want to .
Sorry people for this , but I had to just call a spade a spade, we all are wrong , sometimes , even me , but to demand that he is the best and his product is the best , because he said so , and then to spread erroneous facts , I just couldn’t sit back.
I dont know how you get lead around by your nose so easily, but your cam grinder is
WRONG!!!.
Firstly, there is no such thing as cast nodular steel COMP. It does not exist. Nodules are formed in ductile cast iron while it is cooling by adding magnesium. Hence Ductile Iron is often called Nodular Cast Iron. And No, the Cummins cam is not hardened deep. Hardening any cast iron makes it more brittle. The idea behind any
surface hardening is to raise the wear resistance and keep the inner core ductile and softer so it wont crack/break. This is why Cummins cams are chilled cast ( the same as ours COMP ) The chilled mold hardens the surface but does not make the core hard/brittle and prone to breakage. The very nature of chill casting does not give a a consant hardness throughout the depth. The iron gets softer the further away it gets from the chilled mold. It may be 60RC on the surface and 2mm down it could be 50 and further down it could go to 45 or less.
That cam picture is of Gus Farmers. He took the pictures and used them to blackmail me into a free cam after he repeatedly overheated his engine. Watch the video of the water pouring out of the engine on the dyno. He drove it all over the countryside like that. Constantly overheating it. Any cam can be destroyed like that.
You blame the cam as a lobe failure, but dont have enough knowledge to even understand what your own cam is made of. We tracked that blank back to the same batch of 200 pieces made in 2005 for us. None of the other cams have had failures, over a year later. As a matter of fact we have
NEVER had a cam lobe failure other than Gus Farmer. Not one, not anywhere. Total sales are nearing 400 pieces now with 154 more pieces in production and ol Gus Farmer is the only guy with a lobe failure? Come on now COMPY.
Gus destroyed the engine by overheating it repeatedly.
I know you dont understand that the Cummins B series camshaft is the highest wearing item in the engine, baring nothing else. But it is. This is precisely why Cummins, SWRI and many other companies tested the newest oil and cam wear is the area they test. Cummis has a specific cam wear test for the Cummins ISBe COMP.
Now, I hope you are sitting down cuz this part may hurt. I know without a doubt at this point that the ISBe is dropping valve seats like no other engine in the past because the valves are banging against the seats and poping them loose. Even stock engines. Ever wonder why? Well I did since the early ones that began to pop out.
It is a 2 part problem, aggressive cam lobe design and ineffective valve springs. Yes, the Cummins ISBe has an aggressive lobe. They did not lower the total lift but dropped the duration 10 degrees. This means the cam will raise and lower the valve faster. The ISBe is only one dropping the seats like this. The springs are the same ones from back in 1998 with the first ISB 24V.
Aggressive lobes like you tout are a receipe for disaster in the CR engines, plain and simple.
Springs: Good springs control those valves and since using them we have never had a seat failure. Not one customer. And you have been telling people to shim their stock springs? LOL
The Helix lobes are not wimpy, but they are not a design that allows seat failure through loss of vavle control either. They are right at the line minus a bit for fudge factor. You can continue to dig yourself into a hole with absence of facts about your cam material and tell the world you have a faster cam lobe, but that is your call.
Does it seem strange that some of my customers have gained over 100 FT lbs of TQ by changing out those stock springs you tell people to shim up? :hehe:
